For some of portable electronic apparatuses (portable information terminals), such as a laptop personal computer (laptop PC), a tablet personal computer (tablet PC), and a smartphone, a pen-type input device is used as an input device for touch operation.
For instance, JP H06-110595 A discloses a tablet PC including a hole-shaped storage part in the apparatus casing that has a small diameter and is long to store a pen-type input device (stylus) by insertion. This pen-type input device includes a rechargeable secondary battery built therein, and the storage part of the apparatus casing is provided with a switch to supply electricity for charging of the secondary battery when the switch is connected to a charging terminal provided on a side of the pen-type input device. With this configuration, charging can be performed simply by storing the pen-type input device in the storage part, whereby battery exhaustion of the pen-type input device can be prevented.